Nuñez started his comedy career in New York, founding and performing over 300 shows with The Shock of the Funny theater company. The troupe was active in the East Village for several years. In addition to his work with Shock, Nuñez appeared in theater in New York and Washington, D.C. before moving to Los Angeles in the mid 1990s. In LA, he joined The Groundlings and performed in their Sunday Company. While with the Groundlings, he wrote and starred in a production called "Smooth Down There."

In 1997, Nuñez graduated from the Warner Brothers Comedy Writer’s Workshop. In 1999, he was a finalist in the ABC Latino Writers Project.

In 1998, he appeared on the game show Match Game, wearing a DIO shirt, but was not a winner.

Nuñez appeared as one of eight judges in the 2010 Miss USA Contest, posing a controversial question about the Arizona illegal immigrant law to Miss Oklahoma USA, Morgan Elizabeth Woolard, the first runner-up. Nuñez was booed by the audience before finishing the question, however he asked the audience to wait until he finished the question before they reacted. Although Miss Woolard replied that she supports the law as a state rights issue, she added that she is against racial profiling.[2]